Optimization of fermentation parameters for the valorization of tomato pomace into biomass to produce single cell protein using Saccharomyces cerevisiae.

Tomato pomace, a byproduct of tomato processing industry, can be utilized through fermentation to produce single cell protein (SCP). In this study, fermentation parameters were optimized in a 3-L bioreactor using a full factorial design (FFD), to which a second order polynomial regression model was subsequently fitted to locate the optimum via response surface analysis. While pH, temperature, agitation speed and airflow rate were held constant, the effects of solid load, inoculum volume, and fermentation period were analyzed using a 3 × 3 × 5 experimental design. The resulting biomass was harvested, and its protein content was analyzed. Optimal conditions were identified as a 10.35% solid load and a 2.07% inoculum volume over a 5-day fermentation period. Under these optimized conditions, the model-predicted dry cell weight of 6.92 g/L was validated experimentally at 6.25 g/L, with protein content of 38.40%. These results demonstrate the effective valorization of tomato industry waste into a high value protein resource through optimized bioprocessing.